<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app">{{msg}}</div>
</body>
<script>
    var vm = new Vue({
        el: "#app",
        // template: `<div id='app'></div>`,
      data: {
        msg: "bbb",
      },
      beforeMount() {
        console.log('1111',this.$el);
      },
      mounted() {
        console.log('22222222',this.$el);
      },
    })
</script>
</html>